Best prefab & modular ADU companies in California

Twelve companies. Real price differences. Find the right fit for your backyard.

Our 2026 guide compares installed costs, what the quote leaves out, timelines and company track records.

Samara Backyard XL 8, an 800 sq ft two-bedroom steel-clad ADU, in a backyard — Photo: Courtesy of Samara

By the Renology editorial team · Reviewed by Dror Gigi, Co-Founder · Facts checked September 26, 2026

The short answer

Planning a primary residence? Compare modular homes in California.

A prefab ADU in California costs about $155,000 to $498,800 all-in as of September 2026, based on the companies here that publish a full installed price. Perpetual Homes has the highest editorial score. Abodu publishes the clearest exclusions. USModular and Boxabl publish the lowest turnkey prices in this comparison.

A factory price is not a finished-home price. Site work, utilities and permits can change the total. Understand what is included.

Site work is the part most prefab prices leave out. Get it priced by a vetted local ADU contractor

Looking for Connect Homes or Mighty Buildings? They no longer sell ADUs to homeowners. See company status changes.

Start with what matters to you

See all 12

Highest score overallPerpetual Homes ADU8.1/ 10 Know the full price up frontAbodu7.8/ 10 Low turnkey price, Southern CaliforniaUSModular7.8/ 10 Published turnkey price, small unitBoxabl7.8/ 10 Steel-built, design-ledSamara Backyard7.9/ 10 Turnkey in LA, Bay Area and San DiegoVilla Homes7.8/ 10

Compare the companies

Prices checked September 26, 2026

Start with your area and the kind of price a company publishes. Then select two or three companies for a closer look.

Compare the scope, not just the number. Unit prices exclude installation. All-in and turnkey figures can still have site-specific extras. Timelines below identify where the clock starts.

Find a companyPrice basisPublished service area

Regional filters follow each company’s published list. Also check “Statewide or through your own contractor” and confirm your address with the company.

12 of 12 companies · highest editorial score first

Select up to 3 companies to compare details. On small screens, swipe across the table.

Prefab ADU companies in California compared
Company / score	Published price	Timeline	Best fit
01Perpetual Homes ADU8.1 / 10 editorial scoreFull review Compare Perpetual Homes ADU	$123,000–$170,000Home only All-in from the mid $200,000s, per company.	2–4 months On site after delivery; permitting extra.	Low home prices and many floor plans across 24 counties
02Samara Backyard7.9 / 10 editorial scoreFull review Compare Samara Backyard	$152,000–$277,000Unit only Installation extra; quoted after a site visit.	8–9 months Includes about 5 months of permitting.	A design-led, steel-built unit from a well-funded maker
03Abodu7.8 / 10 editorial scoreFull review Compare Abodu	$298,800–$498,800Published all-in 385–1,195 sq ft. Listed exclusions still apply.	9–12 months Includes permits; installation in one day.	Knowing the whole number before you sign
04Boxabl7.8 / 10 editorial scoreFull review Compare Boxabl	$195,000–$210,000Published turnkey California-approved 1- and 2-bedroom models.	About 2 months From the factory; permitting extra.	A clear, published turnkey price on a small unit
05USModular7.8 / 10 editorial scoreFull review Compare USModular	From $155,000Published turnkey San Diego starting price; tiny ADUs from $145,000.	6–9 months From permit submission.	A budget turnkey ADU in the Inland Empire and San Diego
06Villa Homes7.8 / 10 editorial scoreFull review Compare Villa Homes	From about $225,000Published turnkey Model and site conditions affect the total.	9–12 months Published project timeline.	A turnkey build with many floor plans in Los Angeles, the Bay Area and San Diego
07Cover7.8 / 10 editorial scoreFull review Compare Cover	Request a quoteProject-specific No published price list. Owner reports are not quotes.	As little as 4 months 6–8 weeks on site, per company.	Fire-zone lots and fully custom designs in Southern California
08Dvele7.6 / 10 editorial scoreFull review Compare Dvele	$167,400–$283,200Factory price only 532–900 sq ft. Site costs are additional.	6–12 months To move-in.	A high-performance steel home and the longest structural warranty here
09StudioHOME7.6 / 10 editorial scoreFull review Compare StudioHOME (formerly Studio Shed)	$98,029–$191,523Kit only Installation extra; shell kits from $44,304.	4–6 weeks Kit shipping only; permitting separate.	Small studios and hands-on owners
10Azure Printed Homes7.6 / 10 editorial scoreFull review Compare Azure Printed Homes	$89,900–$219,900Unit only 360–900 sq ft. Confirm installation costs.	8–23 days Factory to installed, per company; permits extra.	Early adopters of new materials
11LiveLarge7.6 / 10 editorial scoreFull review Compare LiveLarge	$140,000–$355,000Unit only Installation extra; all-in quote after a site review.	4–6 weeks On site only.	A steel-frame ADU in Silicon Valley
12Plant Prefab7.5 / 10 editorial scoreFull review Compare Plant Prefab	Request a quoteProject-specific Scope varies by project and builder.	Phased schedule Design, factory, site and finish phases quoted separately.	Architect-led custom projects

0 of 3 selected · Choose at least 2.

Editorial scores run from 7.0 to 10; each listed company starts at 7.0. These are our weighted assessments, not customer star ratings. Read the methodology.

The companies, in detail

12 editorial reviews

What stands out, what to ask about, and the facts behind each score.

Perpetual Homes ADU

8.1/ 10
Editorial score

Best for low home prices and many floor plans across 24 counties

An authorized Skyline Homes dealer in Danville that sells factory-built ADUs across 24 California counties and coordinates the project from design to delivery.

Published price: $123,000–$170,000Home only
All-in from the mid $200,000s, per company.
Timeline: 2–4 months
On site after delivery; permitting extra.

Read full review Visit website

What we like

An all-in figure that already includes fees and tax
24 named counties, the longest service list here
A 1-year limited warranty plus 6 years of structural cover through Assurant
A published payment schedule and named financing partners

Worth knowing

Site work is done by a licensed contractor you engage, since Perpetual is a dealer rather than a general contractor
Its site quotes three different starting prices, so ask for a written all-in quote

Price inclusions, coverage, warranty & scoring

Price: Homes from $123,000 (440 sq ft) to $170,000 (1,173 sq ft); all-in from the mid $200,000s, per the company
What the price covers: Catalog prices are the home only. The all-in estimate adds a raised foundation, standard utilities, $9,500 of planning and a $20,000 allowance for city fees
Price per sq ft: $145 to $280 (home only, before site work)
Time to move-in: About 2 to 4 months on site after delivery, per the company; permitting is extra
Serves: 24 California counties, including the Bay Area, Sacramento, the Central Coast, the Central Valley and Los Angeles
How it is built: Factory-built by Skyline Homes (manufactured housing), set on a raised foundation
Warranty: 1-year limited plus a 6-year structural warranty through Assurant
Owner feedback: BBB A+ (accredited), 0 complaints. Birdeye 4.6 from 16 reviews.
Status: Operating

Total installed costStandout
Price transparencyGood
Time to move-inStandard
Build methodStandard
WarrantyGood
Owner feedbackGood
Company stabilityGood
California coverageStandout
Design choiceGood

Sources: Perpetual Homes: areas served · Perpetual Homes: models · Perpetual Homes: financing · BBB profile · Perpetual Homes: model catalog · Perpetual Homes: 10-step process

Samara Backyard

7.9/ 10
Editorial score

Best for a design-led, steel-built unit from a well-funded maker

A steel-framed ADU from Samara, a Redwood City company backed by Airbnb that builds in its own factory.

Published price: $152,000–$277,000Unit only
Installation extra; quoted after a site visit.
Timeline: 8–9 months
Includes about 5 months of permitting.

Read full review Visit website

What we like

A steel volumetric build with state factory approval
Its own factory and strong financial backing
Clear published unit prices
Financing with no payments for 180 days, through Samara Finance

Worth knowing

Installation is quoted per site, so the all-in number comes later
Five models, so less room to customize

Price inclusions, coverage, warranty & scoring

Price: Units from $152,000 (studio) to $277,000 (950 sq ft), plus installation
What the price covers: The unit. Installation is quoted after a site visit and covers design, permits, site prep, foundation, utilities, crane and decks
Price per sq ft: $292 to $362 (unit only, before installation)
Time to move-in: About 8 to 9 months, including about 5 months of permitting
Serves: California
How it is built: Built as complete rooms in the factory (volumetric modular), with a cold-formed steel frame and California's factory-built housing seal from HCD, the state housing department
Warranty: In the purchase contract; ask for it before signing
Owner feedback: Google 5.0 from 15 reviews. BBB A+, 0 complaints. TIME Best Inventions 2024.
Status: Operating and expanding

Total installed costGood
Price transparencyGood
Time to move-inGood
Build methodStandout
WarrantyStandard
Owner feedbackGood
Company stabilityStandout
California coverageGood
Design choiceStandard

Sources: Samara: models and prices · Samara: how it works · Samara: financing · Samara acquires Mexicali factory (GlobeNewswire) · BBB profile

Abodu

7.8/ 10
Editorial score

Best for knowing the whole number before you sign

Abodu sells factory-built backyard homes with a fixed, itemized all-in price in the Bay Area and Greater Los Angeles.

Published price: $298,800–$498,800Published all-in
385–1,195 sq ft. Listed exclusions still apply.
Timeline: 9–12 months
Includes permits; installation in one day.

Read full review Visit website

What we like

The most complete, itemized all-in pricing in California
A written list of exactly what is quoted separately
Pre-approved plans in San Jose and Sonoma County
A one-day installation

Worth knowing

Higher per square foot than most, especially on small models
Some owners report delays, so agree dates in the contract

Company note: Abodu's own site says Bobby Shokri acquired the company in 2025, after reports that summer that the original company had stopped paying some vendors. We found no bankruptcy filing. If you signed before the change, confirm in writing who holds your contract and deposit.

Price inclusions, coverage, warranty & scoring

Price: All-in from $298,800 (385 sq ft studio) to $498,800 (1,195 sq ft)
What the price covers: Design, engineering, permits, sprinklers, delivery, foundation, site work, trenching up to 50 ft, crane up to 100 ft and a project manager
Price per sq ft: $417 to $776 (all-in)
Time to move-in: About 9 to 12 months including permits; installation in one day
Serves: The San Francisco Bay Area and Greater Los Angeles, 90+ cities
How it is built: Factory-built modular, to California's state standard for factory-built housing (HCD)
Warranty: Ask for terms in writing
Owner feedback: Birdeye 4.0 from 81 reviews. Yelp 3.5 from 34. BBB 0 complaints.
Status: Operating under new ownership

Total installed costStandard
Price transparencyStandout
Time to move-inGood
Build methodGood
WarrantyStandard
Owner feedbackStandard
Company stabilityStandard
California coverageGood
Design choiceStandard

Sources: Abodu: pricing · Abodu: fixed pricing and exclusions · Abodu: about (ownership) · August 2025 vendor report (LinkedIn) · Abodu: process · San Jose pre-approved Abodu plans

Boxabl

7.8/ 10
Editorial score

Best for a clear, published turnkey price on a small unit

Boxabl is a Las Vegas manufacturer whose folding Casita units ship on a truck and unfold on site, with California approval for its one- and two-bedroom models.

Published price: $195,000–$210,000Published turnkey
California-approved 1- and 2-bedroom models.
Timeline: About 2 months
From the factory; permitting extra.

Read full review Visit website

What we like

A turnkey price published for every model
335 Casitas delivered across 10 states as of August 2026
Unit and turnkey prices shown side by side
A public company, so its finances are disclosed
A 1-plus-6-year warranty

Worth knowing

Early in California, with the studio not yet confirmed for the state
Little room to customize the fixed Casita shape

Company note: Boxabl's own SEC filing notes financial risk, so paying in stages tied to delivery is sensible.

Price inclusions, coverage, warranty & scoring

Price: Turnkey $195,000 to $210,000 for the California-approved 1- and 2-bedroom
What the price covers: Permits, survey, engineering, utility hookups, foundation, installation, shipping, crane and final inspection, per the company
Price per sq ft: $270 to $291 (turnkey, California-approved models)
Time to move-in: About 2 months from the factory, plus permitting; set and unfolded on site in about a day
Serves: California approval for the 1-bedroom and 2-bedroom Casita; California installs are just starting
How it is built: Folding factory-built modules
Warranty: 1-year manufacturer warranty plus a 6-year extended warranty
Owner feedback: Google 4.7 from 872 reviews for the Las Vegas factory. BBB rating F with 9 closed complaints.
Status: Operating, listed on Nasdaq (BXBL) since July 2026

Total installed costStandout
Price transparencyStandout
Time to move-inGood
Build methodStandard
WarrantyGood
Owner feedbackStandard
Company stabilityStandard
California coverageStandard
Design choiceStandard

Sources: Boxabl: Casita Studio · Boxabl: Casita One Bedroom · Boxabl: Casita Two Bedroom · Boxabl SEC filing, Q2 2026 · Boxabl expands California general contracting (Nasdaq) · BBB profile

USModular

7.8/ 10
Editorial score

Best for a budget turnkey ADU in the Inland Empire and San Diego

A Calimesa modular dealer in business since 2009, selling turnkey ADUs across Southern California.

Published price: From $155,000Published turnkey
San Diego starting price; tiny ADUs from $145,000.
Timeline: 6–9 months
From permit submission.

Read full review Visit website

What we like

One of the lowest turnkey starting prices, including permits and foundation
17 years in business
More than 100 floor plans
A clear list of what the price includes

Worth knowing

Southern California only
A raised pier foundation may not suit every city

Company note: The state contractor board lists a completed 2026 citation on USModular's license, for requesting payment ahead of work completed and for a home improvement contract issue. The license is active through February 2028. The CSLB page does not show the details of the case.

Price inclusions, coverage, warranty & scoring

Price: Turnkey from $155,000 in San Diego (tiny ADUs from $145,000)
What the price covers: Design, permits and fees, raised pier foundation, transport, installation and utility connections to existing lines
Price per sq ft: Not listed per model
Time to move-in: 6 to 9 months from permit submission
Serves: Riverside, San Bernardino and San Diego counties, plus parts of Los Angeles and Orange County
How it is built: Built to California's modular code or the federal HUD code for manufactured homes
Warranty: Ask for terms in writing
Owner feedback: BBB A+, 1 closed complaint. Birdeye 4.1 from 50 reviews.
Status: Operating since 2009

Total installed costStandout
Price transparencyGood
Time to move-inGood
Build methodStandard
WarrantyStandard
Owner feedbackStandard
Company stabilityGood
California coverageStandard
Design choiceGood

Sources: USModular: Southern California ADU FAQ · USModular: backyard ADU in San Diego · CSLB license 943047 · MyADU4Less: pricing

Villa Homes

7.8/ 10
Editorial score

A dark blue Villa ADU with white trim on a multifamily lot — Photo: Courtesy of Villa

Best for a turnkey build with many floor plans in Los Angeles, the Bay Area and San Diego

Villa is a California ADU builder that designs units, has them built in partner factories and handles the project from permits to move-in.

Published price: From about $225,000Published turnkey
Model and site conditions affect the total.
Timeline: 9–12 months
Published project timeline.

Read full review Visit website

What we like

Pre-approved plans in Los Angeles and San Jose
A turnkey price that covers permits and site work
Many floor plans plus a design studio
Strong owner ratings and a clean BBB record

Worth knowing

Current prices were not available for us to check, so get a written quote
The business is widening beyond backyard ADUs, so ask who will run your project

Company note: Villa now describes itself as a homebuilding platform that works with a network of off-site factories and also builds its own neighborhoods, under CEO Sean Roberts.

Price inclusions, coverage, warranty & scoring

Price: Turnkey from about $225,000
What the price covers: Permits, site and foundation prep, construction, appliances, utility hookups and installation, per Dwell
Price per sq ft: About $258 to $442 (from 2023 model prices)
Time to move-in: 9 to 12 months
Serves: Los Angeles, the Bay Area and San Diego
How it is built: Kiln-dried wood frame, built off-site by partner factories and craned in
Warranty: A standard warranty; ask for the length in writing
Owner feedback: Google 4.7 from 15 reviews. BBB A+ (accredited since January 2026), 0 complaints.
Status: Operating

Total installed costGood
Price transparencyStandard
Time to move-inGood
Build methodGood
WarrantyStandard
Owner feedbackGood
Company stabilityGood
California coverageStandout
Design choiceGood

Sources: Dwell: Villa prefab California ADU builder · Villa delivers first homes at Acacia Village (Newswire) · San Jose pre-approved ADU plans (ADU Plan Finder) · BBB profile

Cover

7.8/ 10
Editorial score

Best for fire-zone lots and fully custom designs in Southern California

A Gardena company that designs custom homes and ADUs and builds them from non-combustible steel panels made in its own factory.

Published price: Request a quoteProject-specific
No published price list. Owner reports are not quotes.
Timeline: As little as 4 months
6–8 weeks on site, per company.

Read full review Visit website

What we like

Non-combustible steel construction, strong for wildfire areas
Fully custom design
A full refund if permits cannot be obtained
Its own Los Angeles-area factory

Worth knowing

A premium price, and no published price list
Southern California only

Price inclusions, coverage, warranty & scoring

Price: Quoted per design, with no published price list. One owner on Reddit reported about $500 per sq ft
What the price covers: Design through construction, with a refund if permits cannot be obtained
Price per sq ft: About $500 (one owner report)
Time to move-in: As little as 4 months for an ADU; 6 to 8 weeks on site
Serves: Ten Southern California counties, from San Luis Obispo to San Diego and Imperial
How it is built: Panelized light-gauge steel, non-combustible, no crane needed
Warranty: Ask for terms in writing
Owner feedback: Google 4.7 from 23 reviews.
Status: Operating, with a growing focus on custom homes and fire rebuilds

Total installed costStandard
Price transparencyStandard
Time to move-inGood
Build methodStandout
WarrantyStandard
Owner feedbackGood
Company stabilityGood
California coverageStandard
Design choiceStandout

Sources: Cover: FAQ (service area) · Owner report on Reddit · Cover: our process · Cover completes first Palisades rebuild (PR Newswire) · CSLB license 1039029 · Cover completes first ADU in Redondo Beach (PR Newswire)

Dvele

7.6/ 10
Editorial score

Best for a high-performance steel home and the longest structural warranty here

A steel modular maker, now based in Mesa, Arizona, that sells finished modules for your own contractor to install.

Published price: $167,400–$283,200Factory price only
532–900 sq ft. Site costs are additional.
Timeline: 6–12 months
To move-in.

Read full review Visit website

What we like

The longest published structural warranty here (2, 5 and 10 years)
Solar and battery storage available
A steel, high-performance build
Model prices published

Worth knowing

Sold as a product, so you manage the site contractor
Site work and design and permit fees are on top of the factory price

Price inclusions, coverage, warranty & scoring

Price: ADU-size models from $167,400 (532 sq ft) to $283,200 (900 sq ft), factory price
What the price covers: The home, including electrical, plumbing, mechanical, finishes and appliances. Delivery, site work, installation and $15,000 to $100,000 of design and permit fees are extra
Price per sq ft: About $315 (factory price only)
Time to move-in: 6 to 12 months to move-in
Serves: California, as a product you install through your own contractor; currently prioritizing Altadena fire rebuilds
How it is built: Built as complete rooms in the factory (volumetric modular), with a steel frame
Warranty: 2-year fit and finish, 5-year on the building shell, 10-year structural
Owner feedback: BBB A+, 0 complaints.
Status: Operating, now headquartered in Mesa, Arizona

Total installed costStandard
Price transparencyGood
Time to move-inGood
Build methodStandout
WarrantyStandout
Owner feedbackStandard
Company stabilityGood
California coverageStandard
Design choiceStandard

Sources: Dvele: homes · Dvele: FAQ · Dvele: Altadena rebuild program

StudioHOME

7.6/ 10
Editorial score

Best for small studios and hands-on owners

The company formerly called Studio Shed sells panelized kits, installed by its network of certified assemblers or by you.

Published price: $98,029–$191,523Kit only
Installation extra; shell kits from $44,304.
Timeline: 4–6 weeks
Kit shipping only; permitting separate.

Read full review Visit website

What we like

Kit prices published for every model
A long track record, with more than 6,000 projects
No crane needed, which helps on tight lots
Choose DIY, a shell, or a fully finished install

Worth knowing

Installation and site work are priced separately
Some buyers report difficulty finding a local installer

Price inclusions, coverage, warranty & scoring

Price: Finished models from $98,029 (308 sq ft) to $191,523 (1,000 sq ft), plus installation; shell kits from $44,304
What the price covers: The kit. Installation, foundation, delivery and permits are extra
Price per sq ft: $192 to $318 (kit only)
Time to move-in: Kits ship in 4 to 6 weeks; permitting is separate
Serves: Northern California and, per a new company page, Los Angeles, Orange and San Diego counties
How it is built: Panelized kit, no crane, Title 24 and zero-net-energy ready
Warranty: 1 year on materials and workmanship
Owner feedback: Google 4.3 from 63 reviews. BBB A+, 1 complaint.
Status: Operating, renamed from Studio Shed in March 2025

Total installed costGood
Price transparencyGood
Time to move-inGood
Build methodGood
WarrantyStandard
Owner feedbackGood
Company stabilityGood
California coverageGood
Design choiceGood

Sources: StudioHOME: models · StudioHOME: Northern California · Studio Shed becomes StudioHOME (PR Newswire) · StudioHOME: Southern California · StudioHOME: process

Azure Printed Homes

7.6/ 10
Editorial score

Best for early adopters of new materials

A Gardena company that 3D-prints ADUs from recycled polymer, with a claimed install time measured in days.

Published price: $89,900–$219,900Unit only
360–900 sq ft. Confirm installation costs.
Timeline: 8–23 days
Factory to installed, per company; permits extra.

Read full review Visit website

What we like

Low unit prices
Very fast installation, per the company
A 10-year warranty
Named to TIME Best Inventions 2025

Worth knowing

A newer building method with a short track record
Check which models are on your city's approved list

Price inclusions, coverage, warranty & scoring

Price: Models from $89,900 (360 sq ft) to $219,900 (900 sq ft)
What the price covers: The unit; confirm what installation adds
Price per sq ft: $244 to $250 (unit only)
Time to move-in: 8 to 23 days from factory to installed, per the company; permits are extra
Serves: California, per the company
How it is built: 3D-printed recycled polymer with fiberglass, plus steel
Warranty: 10 years on materials and workmanship, plus 15 years on the UV coating, per the company
Owner feedback: Google 5.0 from 5 reviews. Named to TIME Best Inventions 2025.
Status: Operating, raising funds through Wefunder

Total installed costGood
Price transparencyStandard
Time to move-inGood
Build methodStandard
WarrantyGood
Owner feedbackStandard
Company stabilityStandard
California coverageGood
Design choiceStandard

Sources: Azure: models · Azure mid-year milestones (GlobeNewswire) · TIME Best Inventions 2025 · Azure: FAQ

LiveLarge

7.6/ 10
Editorial score

Best for a steel-frame ADU in Silicon Valley

A San Jose maker of steel-frame, fire-resistant ADUs with a published model price list.

Published price: $140,000–$355,000Unit only
Installation extra; all-in quote after a site review.
Timeline: 4–6 weeks
On site only.

Read full review Visit website

What we like

A published price for every model
Steel frame, built for fire-prone areas
A 10-year structural warranty
One fixed all-in quote after a site review

Worth knowing

The all-in number comes after a site review
Less independent review history so far

Price inclusions, coverage, warranty & scoring

Price: Models from $140,000 (350 sq ft) to $355,000 (1,190 sq ft), before installation
What the price covers: The unit. LiveLarge then gives one fixed all-in quote covering permits, site work, delivery and installation after a site review
Price per sq ft: $298 to $400 (unit only, before installation)
Time to move-in: 4 to 6 weeks on site
Serves: The Bay Area, with deliveries also listed in Altadena and Los Angeles
How it is built: Steel frame, fire-resistant for wildland-urban interface areas, with a state (HCD) insignia on each unit, per the company
Warranty: 10-year structural, 5-year doors and windows, 2-year plumbing and electrical
Owner feedback: Google 5.0 from 15 reviews.
Status: Operating

Total installed costGood
Price transparencyStandard
Time to move-inGood
Build methodGood
WarrantyGood
Owner feedbackGood
Company stabilityStandard
California coverageGood
Design choiceGood

Sources: LiveLarge: models and prices · LiveLarge: FAQ (warranty, HCD) · LiveLarge: models

Plant Prefab

7.5/ 10
Editorial score

Best for architect-led custom projects

A large California factory that builds custom and LivingHome designs, mostly through architects and general contractors.

Published price: Request a quoteProject-specific
Scope varies by project and builder.
Timeline: Phased schedule
Design, factory, site and finish phases quoted separately.

Read full review Visit website

What we like

A large factory in California
Flexible panel and module system
Custom and LivingHome designs
A clear, published phase-by-phase timeline

Worth knowing

Usually bought through an architect or contractor rather than directly
No published prices

Price inclusions, coverage, warranty & scoring

Price: Quoted per project
What the price covers: Varies by project and by the builder you work with
Price per sq ft: Not published
Time to move-in: Design 4 to 6 weeks, fabrication 8 to 16 weeks, site work 8 to 16 weeks, finish 6 to 12 weeks
Serves: California, mainly through general contractors and architects
How it is built: Hybrid panels and modules, with third-party state-certified inspection
Warranty: Ask for terms in writing
Owner feedback: Google 4.7 from 21 reviews.
Status: Operating

Total installed costStandard
Price transparencyStandard
Time to move-inGood
Build methodStandout
WarrantyStandard
Owner feedbackGood
Company stabilityGood
California coverageGood
Design choiceStandout

Sources: Plant Prefab: models · Plant Prefab: wildfire help (timeline) · The Planning Report interview, February 2026

Also an option: a manufactured-home ADU through a dealer

Large manufactured-home builders such as Cavco (Palm Harbor, Fleetwood) and Skyline Champion (Silvercrest) make ADU-size models in California factories, sold through local dealers. Base prices listed by one dealer run from $78,607 to $119,173 for 744 to 1,173 sq ft, before delivery, setup, tax and site work. They are built to the federal HUD code, the national standard for manufactured homes, and must sit on a permanent foundation to count as an ADU. The all-in cost depends on the dealer and your site, so compare two dealer quotes. We do not score this route because terms vary dealer by dealer.

Sources: Homes Direct ADU list · Silvercrest 790 ADU

Prefab ADU companies by region: Los Angeles, Bay Area, San Diego and Sacramento

Based on the service areas each company publishes. Companies marked statewide still quote per site, so confirm your address before a deposit.

Prefab ADU companies serving each California region
Region	Companies that list it
Los Angeles	Abodu, Villa Homes, Cover, Perpetual Homes ADU, USModular, LiveLarge, StudioHOME (USModular serves parts of LA County.)
Bay Area and Silicon Valley	Abodu, Villa Homes, Perpetual Homes ADU, LiveLarge, StudioHOME
San Diego	Villa Homes, USModular, Cover, StudioHOME
Orange County and the Inland Empire	USModular, Cover, StudioHOME
Sacramento and the Central Valley	Perpetual Homes ADU, StudioHOME
Statewide or through your own contractor	Samara Backyard, Boxabl, Azure Printed Homes, Plant Prefab, Dvele

Which prefab ADU companies closed or changed?

Several names that still show up in older lists have closed, been sold or changed what they sell. This is what we found in public records and reporting, checked September 26, 2026.

Prefab ADU company status changes
Company	Status	When	What happened
Connect Homes	Closed	January 2025	Home EC Inc. (doing business as Connect Homes) went through an assignment for the benefit of creditors, an out-of-court liquidation. Its old domain now redirects to a "Connect Shelters" site whose operator we could not confirm. SF Chronicle, via Allen Matkins, Dwell
Mighty Buildings	Sold, no longer sells homes to homeowners	2025	The 3D-printing company was sold and now operates as a LUMUS brand selling wall systems. Mighty Buildings: about, 3D Printing Industry
Abodu	Operating under new ownership	2025	Acquired by Bobby Shokri after reports in August 2025 that the original company had stopped paying some vendors. No bankruptcy filing found. Abodu: about
Villa Homes	Operating, broader model	2026	Now a homebuilding platform using partner factories and building its own neighborhoods, under CEO Sean Roberts. Still offers ADUs. Newswire
Studio Shed	Renamed StudioHOME	March 2025	Same company, new name. PR Newswire
Dvele	Operating, moved headquarters	2026	Headquarters and a new factory in Mesa, Arizona. Blu Homes is now part of Dvele. Dvele: contact
Cottage	Absorbed by RenoFi	Date not confirmed	The ADU design and permitting service is now part of RenoFi. Cottage on LinkedIn
Avava Systems	Closed	Date not confirmed	The flat-pack ADU maker no longer operates. Dwellito
Anchored Tiny Homes	Closed	July 2024	The Sacramento ADU builder shut down abruptly. ABC7
Veev	Closed	November 2023	The panelized home builder shut down. The Real Deal
Katerra	Closed	June 2021	Filed for Chapter 11 and wound down US operations. ENR
Nestron	Operating, no California ADU approval stated	2026	Units are made in Shenzhen and sold from a Cabazon showroom. We found no California factory-built approval, so we do not rank it. Nestron: about

How to protect your deposit

California caps a home-improvement down payment at $1,000 or 10% of the contract, whichever is less.
Ask for a payment schedule tied to delivery and installation, not to the calendar.
Look up the company's license, bond and workers' comp on the CSLB website before you sign.

Unit price vs all-in price

Prefab prices are published in two different ways, and mixing them up is an easy way to under-budget. Some companies publish a unit price: the building, delivered or ready to ship. Samara, Dvele, StudioHOME, LiveLarge and Azure work this way. Others publish an all-in price that includes permits, foundation, utility connections and installation: Abodu, Boxabl's turnkey option, USModular, Perpetual Homes and Villa.

The gap between the two is site work. Abodu, the only company here that itemizes it, prices installation at $64,000 to $105,000 depending on the model, and still lists a survey, long trenching runs, long crane reaches, tree removal and sales tax as extras. On the published all-in prices, a finished prefab ADU runs roughly $258 to $776 per square foot, with small studios at the top of that range because site work costs about the same whatever the size.

For a line-by-line look at what 13 companies publish and what their prices leave out, read our guide to what prefab ADU prices include. For the full ADU picture, including garage conversions and site-built units, see our California ADU construction cost and permit guide.

The part most prefab prices leave out

Get your site work checked by a local contractor

Foundation, trenching, utility connections and crane access decide most of the gap between a sticker price and a finished ADU. A licensed local contractor can walk your yard and price that part before you sign with a factory.

Comparing a factory unit with a garage conversion or a site-built ADU? Our ADU construction cost and permit guide sets the three paths side by side.

Find a vetted ADU contractor

How we score

To be listed, a company must be operating, sell factory-built ADUs to California homeowners, and hold state approval or build to California code. Every listed company starts at 7.0. It can earn up to 3 more points across nine criteria, in proportion to each criterion's weight. Information a company does not publish counts as neutral, never against it. No company pays to be listed or to change its score, and scores are updated when the facts change.

Scoring criteria and weights
Criterion	Weight	What we look at
Total installed cost	20%	How far a dollar goes once the unit is actually installed and permitted, from published all-in prices where they exist.
Price transparency	15%	Whether a homeowner can see a price, and what it covers, before a sales call.
Time to move-in	10%	The published window from contract to a finished unit.
Build method	10%	A proven factory method with state approval, and how well the finished shell (walls, roof, windows) holds up.
Warranty	10%	Published warranty terms, especially structural coverage.
Owner feedback	10%	What owners say on Google, BBB and other public review sites.
Company stability	10%	Track record, funding and ownership, read from public records and news.
California coverage	10%	How much of California the company serves, and pre-approved plans in city programs.
Design choice	5%	How many plans there are and how far they can be changed.

Sources are company websites, pricing and FAQ pages, SEC filings, BBB, Google reviews, city pre-approved plan lists and news reporting, each linked beside the fact it supports. Found something out of date? Email editor@therenology.com and we will check it.

Change log

September 26, 2026: First published. 12 companies scored, 12 status changes tracked.
September 26, 2026: Added full reviews for the other eight companies, a price per sq ft column and photos. Corrected Perpetual Homes (dealer, home-only catalog prices), Dvele (solar now optional) and LiveLarge (10-year structural warranty).
September 26, 2026: Editorial pass: Boxabl price floor now uses its California-approved models, Perpetual Homes warranty wording corrected, regions table and new FAQs added.
October 1, 2026: Boxabl: promotional pricing ended, turnkey prices updated to $150,000 to $210,000. Added delivery figures from its August 2026 filing and on-site installation time.

Frequently asked questions

How much does a prefab ADU cost in California?

Published all-in prices in California run from about $155,000 to $498,800 as of September 2026, from USModular's turnkey starting price to Abodu's 1,195 sq ft three-bedroom. Unit-only prices start lower, from about $90,000, but site work, foundation, utilities and permits come on top. Abodu, the only company we reviewed that itemizes it, prices installation at $64,000 to $105,000.

Which prefab ADU company is the best in California?

It depends on what you need. In our September 2026 review, Perpetual Homes scored highest overall for a managed all-in build, Samara for a steel-built design-led unit, Abodu for knowing the full price up front, and USModular or Boxabl for the lowest published turnkey prices.

What are the drawbacks of prefab ADUs?

Four are worth knowing. Site work, foundation and utilities still cost about as much as for a site-built ADU and are often priced separately. Most makers offer a handful of fixed floor plans. A crane or truck needs access to your yard. And several prefab companies have closed in recent years, so check a company's license and ask how your deposit is held.

What is the difference between a prefab and a modular ADU?

Prefab is the umbrella term for any ADU built mostly in a factory. A modular ADU is one kind: it arrives as complete rooms (volumetric modules), like Samara, Abodu or Dvele. Other prefab ADUs arrive as wall and roof panels assembled on site, like Cover or StudioHOME, or are built to the federal HUD code for manufactured homes.

Are prefab ADUs worth it?

For many California lots, yes. A factory-built unit usually spends weeks on site instead of months, and several makers publish prices up front. The savings are smaller than the sticker suggests, because site work, foundation and utilities cost about the same as for a site-built ADU.

What is the cheapest way to get a prefab ADU in California?

The lowest published turnkey starting prices are USModular's (from $155,000 in Southern California) and Boxabl's ($195,000 to $210,000 for its California-approved models). Manufactured-home ADUs through dealers can have lower unit prices, but delivery, setup and site work are extra.

Is it cheaper to build or prefab an ADU?

Prefab is usually faster, and sometimes cheaper. Site-built ADUs in California commonly run $300 to $550 per sq ft. Published prefab all-in prices range from about $258 to $776 per sq ft, depending on size and maker.

Do prefab ADUs need a foundation?

Yes. A California ADU sits on a permanent foundation, and your city permits it along with the utility connections. Some makers include it in the price; others quote it separately.

What is the $40,000 grant in California for ADUs, and is it still available?

It was the CalHFA ADU Grant Program, which paid up to $40,000 toward pre-construction costs such as design, permits and impact fees. It has been fully allocated since December 2023 and is not accepting applications. Some cities and counties run their own programs, so check with your local housing department.

What happened to Connect Homes?

Connect Homes closed in January 2025 through an assignment for the benefit of creditors, an out-of-court liquidation, as reported by the San Francisco Chronicle and Dwell.

How do I protect my deposit with a prefab ADU company?

California caps a home-improvement down payment at $1,000 or 10% of the contract, whichever is less. Ask for a payment schedule tied to delivery and installation milestones, and check the company's license on the CSLB website before signing.

Planning a pool too? See our comparison of prefab pools: fiberglass, precast plunge and container pools.